The value of the laser has become recognized in various medical fields. For example, in the field of gynecology, lasers have now been utilized for cervical dysplasia, venereal warts, endometriosis, fallopian tube procedures, and vulvectomys. In the field of dermatology, laser procedures are used to port wine stain removal, tattoo removals, fungal conditions, and the removal of birth marks. Lasers are also used in podiatry for fungal nails, plantars warts, bunionectomys, and neuroma removal. Brain tumors are removed by lasers in neurosurgery, and lasers are also used in endotracheal growth vaporization and removal of carcinoma of the larynx in the pulmonary field.
One problem, however, is that laser surgery is accompanied by the generation of a large amount of smoke from irradiated tissue. In a study conducted by the Department of Otolaryngology and Public Health of Kurume University, Kurume, Japan, it was found that when there was complete vaporization of one gram of tissue, smoke particles are fifty-two times higher than the environmental standards regulated by their government agencies. From this it would appear, that without special measures being taken, the operating room air present while laser surgical procedures are being conducted will be polluted by the smoke induced by laser irradiation and to an unacceptable level.
The same study generated statistics for the following chart which shows the weight concentration relating to particle size, where the particle size is expressed as a percentage of total amount of the particles.
______________________________________ Particle Diameter Particle Distribution (Microns) (Percentage) ______________________________________ 9.0+ 3% 5.8-9.0 3% 4.7-5.8 2% 3.3-4.7 3% 2.1-3.3 4% 1.1-2.1 8% 0.7-1.1 20% 0.4-0.7 37% 0-0.4 20% ______________________________________
It can be seen from the above particle size/distribution that 77 percent of the total number of particles were less than 1.1 micron in size. According to this model, most particles in the smoke are deposited in the respiratory system at what is known in the medical field as the Alveoli level.
It is well known that there is a high correlation between carcinogenic substances and mutagenicity. Therefore, the microbial mutation tests have been made for identification of any possible carcinogenetic substances. The interpretation of the results of such tests have not been definitive, and while it cannot be said that vaporization definitely possesses carcinogenicity the possibility is high and further studies are needed.
In accordance with the present invention, an improved laser smoke particulate/odor filter system is provided whereby the possible problems heretofore alluded to in surgical environments utilizing standard air filtering means are substantially eliminated. That is, the invention provides an advantageous means to preclude contamination air (smoke plume) from the surgical site from entering the surgeon's lungs as well as those of his colleagues.